Securing an AJAX service call in jQuery and PHP (with session token) - javascript

I'm currently building a framework in which for example form submit's are being implemented as jQuery ajax calls to a .php (service) file.
Part of the jQuery for reference:
var dataSerialized = $(form).serialize();
var service = $(form).attr("action");
$.ajax({
url: "services/" + service + ".php",
data: dataSerialized,
type: "POST",
cache: false,
dataType: "json",
success: function(json) {
$(json).each(function() {
loadPage(this.callback);
});
},
error: function(json, message) {
finalError(message);
}
});
And the .php does currently nothing more than:
include_once("../content/includes/connect.php");
include_once("_functions.php");
//TODO: support sending variables
$check = true;
$callback = "error";
foreach ($_POST as $key => $value) {
list($pass, $errormessage) = checkRules("register", $key, $value);
if (!$pass) {
$check = false;
$callback = "error";
break;
}
}
if ($check) {
$callback = "register_success";
}
echo json_encode(array(
"callback" => $callback
));
SQL::close();
Now I want the service call to be as secure as possible, given my situation, I see the following options:
SSL cannot be used, as it is relatively too expensive. Just working on a homebred project, nothing important.
jCryption library cannot be used, as I'm on a cheap web hosting and do not have access to the server itself.
OAuth 2.0 is a possibility, but seems quite complicated.
$_SERVER variables can be used to help protecting the service .php pages, but not reliable.
$_SESSION could be used to generate tokens.
I already implemented an easy measure: Change GET to POST. This will only deter the most easy attack, now the attacker actually needs to use some tampering tool instead of being able to do it directly through the browser.
I think I can protect every call that comes from an URL typed in the browser, however I see two serious threats:
Direct requests to the webserver: The attacker can pass any data he wants.
Using a Browser JavaScript Console to send custom jQuery requests.
I think it is best, again under these circumstances, to try to protect the service .php pages with $_SESSION tokens, but how exactly do I go about these?
They need to be set as some point in time before the service call, and then the service call could check it.
I also have access to a MySQL database and of course plain text files on the webspace.
Can anyone help me out any further?

Have a csrf token send together with the form and in your .php file you could use something like this
session_start();
if ($_SERVER['HTTP_X_CSRF_TOKEN'] !== $_SESSION['csrfToken']) {
return false;
die();
}
Send CSRF Token with all service calls
$.ajaxSetup({
headers: {
'X-Csrf-Token': "TOKEN HERE"
}
});

Related

Send an AJAX email in a Javascript funciton without using PHP

I was handed a website to work on and I'm not very familiar with AJAX. I was hoping there was a simple solution to the URL: portion of the Ajax in order to send an email. I'd rather not use a PHP script in place of what's already there but if needed I can.
This is for a website that's mostly bootstrapped with some simple HTML code and naming conventions are standard.
<script>
$("#btnSend").click(function () {
var email = $('#txtFromEmail').val();
if (($('#txtName').val().length === 0) || (email.length === 0) ||
($('#txtSubject').val().length === 0) || ($('#txtBody').val().length === 0)) {
alert("Please fill out all of the form.");
} else {
var emailModel = {
Name: $('#txtName').val(),
FromEmail: $('#txtFromEmail').val(),
Subject: $('#txtSubject').val(),
Body: $('#txtBody').val()
};
$.ajax({
url: "#Url.Action("Contact", "Main")",
type: 'POST',
contentType: "application/json; charset=utf-8",
data: JSON.stringify(emailModel),
success: function (result) {
if (result.message.length == 0) {
alert("Message Sent Successfully!");
} else {
alert("Message failed to send. Please try again or call the Sports Hub");
}
}
});
}
});
</script>
Ajax can make HTTP requests. That is all.
If you want to send email then you'll need to either:
Use the user's email client (and not Ajax) which is highly unreliable
Make an HTTP request to a web service that will send the email
You could write the web service in PHP, or you could use a different programming language (you seem to be using ASP.NET so any ASP.NET compatible language will do), or you could find a third-party hosted service.
There is no way you can send an email directly from Javascript.
Either you use php or open directly the mail client from the browser:
window.open('mailto:test#example.com');
If you want to pass more parameters you can use the following string:
window.open('mailto:test#example.com?body=body&subject=subject');
you can use an email web service to do this. i replaced my PHP page because it was a pain setting it up when i migrated from godaddy to aws. check out formspree. you will be able to integrate thru the front-end. on your first email you'll have to accept formspree emails, once you do, all other emails will be fwd to you.

can not Send data to php file using ajax

I have this php file graph.php
$host = $_POST['hostname'];
echo $type=$_POST['type_char'];
include('rrdtools.inc.php');
include('graphs/'.$type.'.inc.php');
and I trying to send data to this file using this ajax code
var type_char='fortigate_cpu';//$('#graph').val();
var hostname='10.10.0.144';//$(this).attr('id');
//$('#device_host').val(id);
$.ajax({
type: 'POST',
url: 'SNMP/graph.php',
data: { hostname:hostname,type_char:type_char },
success: function(data) {
alert(data);
// show the response
$("#grph").attr("src", 'SNMP/graph.php');
console.log(data);
}
});
the result when I send data to that file is
fortigate_cpu as a value of type_char variable
when I opened error.log file in apache logs
I have this message
include(): Failed opening 'graphs/.inc.php' for inclusion (include_path='.:/usr/share/php')
as you see the value of fortigate not included in include function even if the char_type variable is send by ajax and printed in page
include file must be as this
include( 'graphs/fortigate_cpu.inc.php')
why type not included in the include session even if the variable is received from ajax
As was mentioned by other users in the comments, maybe your issue is that you are setting type to a different value after including rrdtools.inc.php .
Try randomizing ( changing the name), of the type variable:
$host = $_POST['hostname'];
echo $type123456=$_POST['type_char'];
include('rrdtools.inc.php');
include('graphs/'.$type123456.'.inc.php');
It's the only thing I can think of, since both I (and others) have tested your code.
(both front-end and back-end).
PS: Include using post param is a bad practice.

How to choose the right dataType and contentType value for AJAX request?

I have written some jQuery + PHP code that takes the HTML from an element on a webpage and saves it on server. Here is the code that I am using:
var page = {
'html': document.querySelector("article").innerHTML,
'url': 'path/current/webpage.php' or (<?php echo "'$current_page'"; ?>)
// Both give same 'url' value. This is not an issue.
};
$.ajax({
url:'https://example.com/update.php',
type:'post',
data: page,
success:function(data){
window.location.reload();
}
});
Here is my code for update.php:
$content = $_REQUEST['html'];
$page = $_REQUEST['url'];
file_put_contents($page, $content, LOCK_EX);
I am not very comfortable with dataType and contentType so I skipped them initially. However the request succeeded sometimes but gave 403() error other times.I did a little research and found that this might be due to lack of dataType and contentType. So, I used the following values:
contentType: 'text/plain; charset=utf-8',
dataType: 'html'
I no longer get any errors but the pages are not actually updating. I also tried setting the values to:
contentType:'application/json',
dataType: 'html'
This time too, I did not get any 403() errors but the page would not actually update.
Does the post data needs to be accessed differently based on the value of contentType like 'application/json' or 'text/plain; charset=utf-8'? Because the updates don't seem to show up on the webpage even with a 200 response code.
Using application/x-www-form-urlencoded; charset=UTF-8 updates some pages but gives 403() error for others.
As Rory said (as did I, in an answer I wrote then deleted when I saw his comment; he was right to comment instead), a 403 response code probably doesn't mean there's a problem with either dataType or contentType. You should look for other reasons the server would refuse to satisfy the request. For instance, as you're posting HTML, perhaps you (or your web host) has some kind of anti-script-injection protection going on. You'll have to track that down, perhaps with your hosting company.
But two things: Some info for completeness, and a potential workaround:
dataType is the type you expect back from the server. contentType is the type of data you're sending to the server.
For the request you're sending, leaving off contentType is correct, because the default jQuery will use is what PHP will expect to see.
You shouldn't have to specify dataType at all; instead, you should ensure the response carries the correct Content-Type header. That means ensuring that your server is configured correctly (for static content) and that your PHP code sets the correct header if necessary via header("Content-Type: data/type-here") The only reason for specifying dataType is if you don't control the server and you know it sends back the wrong type.
If you need to try to work around it, first ask: What if someone sends me malicious HTML directly, not through my web page? The answer is: You need to be careful with what you do with the HTML. For example: If you are going to store this HTML and then display it (as HTML) to a user, that's a Cross-Site Scripting vulnerability and you have to rigorously sanitize that HTML before doing that.
Do not proceed with any workaround until you've answered that question for yourself.
Okay, so in terms of working around it (once you have robust safeguards in place): You might send JSON rather than a standard form, in hopes that whatever is rejecting the forms won't look at it. To do that, you'd change your ajax call:
var page = {
html: document.querySelector("article").innerHTML,
url: <?php echo "'$current_page'"; ?>
};
$.ajax({
url:'https://example.com/update.php',
type:'post',
data: JSON.stringify(page),
contentType: 'application/json; charset=UTF8',
success:function(data){
window.location.reload();
}
});
Then on the PHP side, you'd read that JSON and parse it (reading code below taken from this answer):
$entityBody = json_decode(stream_get_contents(STDIN));
$content = $entityBody['html'];
$page = $entityBody['url'];
file_put_contents($page, $content, LOCK_EX);
Again: Please do not use this unless you have robust anti-XSS safeguards in place. And again, if you do haev robust anti-XSS safeguards in place, you might be able to just use a normal form by changing your server config.

Cross Domain Error in post request [duplicate]

How do I send a cross-domain POST request via JavaScript?
Notes - it shouldn't refresh the page, and I need to grab and parse the response afterwards.
Update: Before continuing everyone should read and understand the web.dev tutorial on CORS. It is easy to understand and very clear.
If you control the server being POSTed, simply leverage the "Cross-Origin Resource Sharing standard" by setting response headers on the server. This answer is discussed in other answers in this thread, but not very clearly in my opinion.
In short here is how you accomplish the cross domain POST from from.com/1.html to to.com/postHere.php (using PHP as an example). Note: you only need to set Access-Control-Allow-Origin for NON OPTIONS requests - this example always sets all headers for a smaller code snippet.
In postHere.php setup the following:
switch ($_SERVER['HTTP_ORIGIN']) {
case 'http://from.com': case 'https://from.com':
header('Access-Control-Allow-Origin: '.$_SERVER['HTTP_ORIGIN']);
header('Access-Control-Allow-Methods: GET, PUT, POST, DELETE, OPTIONS');
header('Access-Control-Max-Age: 1000');
header('Access-Control-Allow-Headers: Content-Type, Authorization, X-Requested-With');
break;
}
This allows your script to make cross domain POST, GET and OPTIONS. This will become clear as you continue to read...
Setup your cross domain POST from JS (jQuery example):
$.ajax({
type: 'POST',
url: 'https://to.com/postHere.php',
crossDomain: true,
data: '{"some":"json"}',
dataType: 'json',
success: function(responseData, textStatus, jqXHR) {
var value = responseData.someKey;
},
error: function (responseData, textStatus, errorThrown) {
alert('POST failed.');
}
});
When you do the POST in step 2, your browser will send a "OPTIONS" method to the server. This is a "sniff" by the browser to see if the server is cool with you POSTing to it. The server responds with an "Access-Control-Allow-Origin" telling the browser its OK to POST|GET|ORIGIN if request originated from "http://from.com" or "https://from.com". Since the server is OK with it, the browser will make a 2nd request (this time a POST). It is good practice to have your client set the content type it is sending - so you'll need to allow that as well.
MDN has a great write-up about HTTP access control, that goes into detail of how the entire flow works. According to their docs, it should "work in browsers that support cross-site XMLHttpRequest". This is a bit misleading however, as I THINK only modern browsers allow cross domain POST. I have only verified this works with safari,chrome,FF 3.6.
Keep in mind the following if you do this:
Your server will have to handle 2 requests per operation
You will have to think about the security implications. Be careful before doing something like 'Access-Control-Allow-Origin: *'
This wont work on mobile browsers. In my experience they do not allow cross domain POST at all. I've tested android, iPad, iPhone
There is a pretty big bug in FF < 3.6 where if the server returns a non 400 response code AND there is a response body (validation errors for example), FF 3.6 wont get the response body. This is a huge pain in the ass, since you cant use good REST practices. See bug here (its filed under jQuery, but my guess is its a FF bug - seems to be fixed in FF4).
Always return the headers above, not just on OPTION requests. FF needs it in the response from the POST.
If you control the remote server, you should probably use CORS, as described in this answer; it's supported in IE8 and up, and all recent versions of FF, GC, and Safari. (But in IE8 and 9, CORS won't allow you to send cookies in the request.)
So, if you don't control the remote server, or if you have to support IE7, or if you need cookies and you have to support IE8/9, you'll probably want to use an iframe technique.
Create an iframe with a unique name. (iframes use a global namespace for the entire browser, so pick a name that no other website will use.)
Construct a form with hidden inputs, targeting the iframe.
Submit the form.
Here's sample code; I tested it on IE6, IE7, IE8, IE9, FF4, GC11, S5.
function crossDomainPost() {
// Add the iframe with a unique name
var iframe = document.createElement("iframe");
var uniqueString = "CHANGE_THIS_TO_SOME_UNIQUE_STRING";
document.body.appendChild(iframe);
iframe.style.display = "none";
iframe.contentWindow.name = uniqueString;
// construct a form with hidden inputs, targeting the iframe
var form = document.createElement("form");
form.target = uniqueString;
form.action = "http://INSERT_YOUR_URL_HERE";
form.method = "POST";
// repeat for each parameter
var input = document.createElement("input");
input.type = "hidden";
input.name = "INSERT_YOUR_PARAMETER_NAME_HERE";
input.value = "INSERT_YOUR_PARAMETER_VALUE_HERE";
form.appendChild(input);
document.body.appendChild(form);
form.submit();
}
Beware! You won't be able to directly read the response of the POST, since the iframe exists on a separate domain. Frames aren't allowed to communicate with each other from different domains; this is the same-origin policy.
If you control the remote server but you can't use CORS (e.g. because you're on IE8/IE9 and you need to use cookies), there are ways to work around the same-origin policy, for example by using window.postMessage and/or one of a number of libraries allowing you to send cross-domain cross-frame messages in older browsers:
Porthole
XSSInterface
EasyXDM
jQuery PostMessage Plugin
If you don't control the remote server, then you can't read the response of the POST, period. It would cause security problems otherwise.
Create an iFrame,
put a form in it with Hidden inputs,
set the form's action to the URL,
Add iframe to document
submit the form
Pseudocode
var ifr = document.createElement('iframe');
var frm = document.createElement('form');
frm.setAttribute("action", "yoururl");
frm.setAttribute("method", "post");
// create hidden inputs, add them
// not shown, but similar (create, setAttribute, appendChild)
ifr.appendChild(frm);
document.body.appendChild(ifr);
frm.submit();
You probably want to style the iframe, to be hidden and absolutely positioned. Not sure cross site posting will be allowed by the browser, but if so, this is how to do it.
Keep it simple:
cross-domain POST:
use crossDomain: true,
shouldn't refresh the page:
No, it will not refresh the page as the success or error async callback will be called when the server send back the response.
Example script:
$.ajax({
type: "POST",
url: "http://www.yoururl.com/",
crossDomain: true,
data: 'param1=value1&param2=value2',
success: function (data) {
// do something with server response data
},
error: function (err) {
// handle your error logic here
}
});
If you have access to all servers involved, put the following in the header of the reply for the page being requested in the other domain:
PHP:
header('Access-Control-Allow-Origin: *');
For example, in Drupal's xmlrpc.php code you would do this:
function xmlrpc_server_output($xml) {
$xml = '<?xml version="1.0"?>'."\n". $xml;
header('Connection: close');
header('Content-Length: '. strlen($xml));
header('Access-Control-Allow-Origin: *');
header('Content-Type: application/x-www-form-urlencoded');
header('Date: '. date('r'));
// $xml = str_replace("\n", " ", $xml);
echo $xml;
exit;
}
This probably creates a security problem, and you should make sure that you take the appropriate measures to verify the request.
Check the post_method function in http://taiyolab.com/mbtweet/scripts/twitterapi_call.js - a good example for the iframe method described above.
Create two hidden iframes (add "display: none;" to the css style). Make your second iframe point to something on your own domain.
Create a hidden form, set its method to "post" with target = your first iframe, and optionally set enctype to "multipart/form-data" (I'm thinking you want to do POST because you want to send multipart data like pictures?)
When ready, make the form submit() the POST.
If you can get the other domain to return javascript that will do Cross-Domain Communication With Iframes (http://softwareas.com/cross-domain-communication-with-iframes) then you are in luck, and you can capture the response as well.
Of course, if you want to use your server as a proxy, you can avoid all this. Simply submit the form to your own server, which will proxy the request to the other server (assuming the other server isn't set up to notice IP discrepancies), get the response, and return whatever you like.
One more important thing to note!!!
In example above it's described how to use
$.ajax({
type : 'POST',
dataType : 'json',
url : 'another-remote-server',
...
});
JQuery 1.6 and lower has a bug with cross-domain XHR.
According to Firebug no requests except OPTIONS were sent. No POST. At all.
Spent 5 hours testing/tuning my code. Adding a lot of headers on the remote server (script). Without any effect.
But later, I've updated JQuery lib to 1.6.4, and everything works like a charm.
If you want to do this in ASP.net MVC environment with JQuery AJAX, follow these steps:
(this is a summary of the solution offered at this thread)
Assume that "caller.com"(can be any website) needs to post to "server.com"(an ASP.net MVC application)
On the "server.com" app's Web.config add the following section:
<httpProtocol>
<customHeaders>
<add name="Access-Control-Allow-Origin" value="*" />
<add name="Access-Control-Allow-Headers" value="Content-Type" />
<add name="Access-Control-Allow-Methods" value="POST, GET, OPTIONS" />
</customHeaders>
</httpProtocol>
On the "server.com", we'll have the following action on the controller(called "Home") to which we will be posting:
[HttpPost]
public JsonResult Save()
{
//Handle the post data...
return Json(
new
{
IsSuccess = true
});
}
Then from the "caller.com", post data from a form(with the html id "formId") to "server.com" as follow:
$.ajax({
type: "POST",
url: "http://www.server.com/home/save",
dataType: 'json',
crossDomain: true,
data: $(formId).serialize(),
success: function (jsonResult) {
//do what ever with the reply
},
error: function (jqXHR, textStatus) {
//handle error
}
});
There is one more way (using html5 feature). You can use proxy iframe hosted on that other domain, you send message using postMessage to that iframe, then that iframe can do POST request (on same domain) and postMessage back with reposnse to the parent window.
parent on sender.com
var win = $('iframe')[0].contentWindow
function get(event) {
if (event.origin === "http://reciver.com") {
// event.data is response from POST
}
}
if (window.addEventListener){
addEventListener("message", get, false)
} else {
attachEvent("onmessage", get)
}
win.postMessage(JSON.stringify({url: "URL", data: {}}),"http://reciver.com");
iframe on reciver.com
function listener(event) {
if (event.origin === "http://sender.com") {
var data = JSON.parse(event.data);
$.post(data.url, data.data, function(reponse) {
window.parent.postMessage(reponse, "*");
});
}
}
// don't know if we can use jQuery here
if (window.addEventListener){
addEventListener("message", listener, false)
} else {
attachEvent("onmessage", listener)
}
High level.... You need to have a cname setup on your server so that other-serve.your-server.com points to other-server.com.
Your page dynamically creates an invisible iframe, which acts as your transport to other-server.com. You then have to communicate via JS from your page to the other-server.com and have call backs that return the data back to your page.
Possible but requires coordination from your-server.com and other-server.com
I think the best way is to use XMLHttpRequest (e.g. $.ajax(), $.post() in jQuery) with one of Cross-Origin Resource Sharing polyfills https://github.com/Modernizr/Modernizr/wiki/HTML5-Cross-Browser-Polyfills#wiki-CORS
This is an old question, but some new technology might help someone out.
If you have administrative access to the other server then you can use the opensource Forge project to accomplish your cross-domain POST. Forge provides a cross-domain JavaScript XmlHttpRequest wrapper that takes advantage of Flash's raw socket API. The POST can even be done over TLS.
The reason you need administrative access to the server you are POSTing to is because you must provide a cross-domain policy that permits access from your domain.
http://github.com/digitalbazaar/forge
I know this is an old question, but I wanted to share my approach. I use cURL as a proxy, very easy and consistent. Create a php page called submit.php, and add the following code:
<?
function post($url, $data) {
$header = array("User-Agent: " . $_SERVER["HTTP_USER_AGENT"], "Content-Type: application/x-www-form-urlencoded");
$curl = curl_init();
curl_setopt($curl, CURLOPT_URL, $url);
curl_setopt($curl, CURLOPT_HTTPHEADER, $header);
curl_setopt($curl, CURLOPT_RETURNTRANSFER, 1);
curl_setopt($curl, CURLOPT_POST, 1);
curl_setopt($curl, CURLOPT_POSTFIELDS, $data);
$response = curl_exec($curl);
curl_close($curl);
return $response;
}
$url = "your cross domain request here";
$data = $_SERVER["QUERY_STRING"];
echo(post($url, $data));
Then, in your js (jQuery here):
$.ajax({
type: 'POST',
url: 'submit.php',
crossDomain: true,
data: '{"some":"json"}',
dataType: 'json',
success: function(responseData, textStatus, jqXHR) {
var value = responseData.someKey;
},
error: function (responseData, textStatus, errorThrown) {
alert('POST failed.');
}
});
Should be possible with a YQL custom table + JS XHR, take a look at:
http://developer.yahoo.com/yql/guide/index.html
I use it to do some client side (js) html scraping, works fine
(I have a full audio player, with search on internet/playlists/lyrics/last fm informations, all client js + YQL)
CORS is for you.
CORS is "Cross Origin Resource Sharing", is a way to send cross domain request.Now the XMLHttpRequest2 and Fetch API both support CORS, and it can send both POST and GET request
But it has its limits.Server need to specific claim the Access-Control-Allow-Origin, and it can not be set to '*'.
And if you want any origin can send request to you, you need JSONP (also need to set Access-Control-Allow-Origin, but can be '*')
For lots of request way if you don't know how to choice, I think you need a full functional component to do that.Let me introduce a simple component https://github.com/Joker-Jelly/catta
If you are using modern browser (> IE9, Chrome, FF, Edge, etc.), Very Recommend you to use a simple but beauty component https://github.com/Joker-Jelly/catta.It have no dependence, Less than 3KB, and it support Fetch, AJAX and JSONP with same deadly sample syntax and options.
catta('./data/simple.json').then(function (res) {
console.log(res);
});
It also it support all the way to import to your project, like ES6 module, CommonJS and even <script> in HTML.
If you have access to the cross domain server and don't want to make any code changes on server side, you can use a library called - 'xdomain'.
How it works:
Step 1:
server 1: include the xdomain library and configure the cross domain as a slave:
<script src="js/xdomain.min.js" slave="https://crossdomain_server/proxy.html"></script>
Step 2:
on cross domain server, create a proxy.html file and include server 1 as a master:
proxy.html:
<!DOCTYPE HTML>
<script src="js/xdomain.min.js"></script>
<script>
xdomain.masters({
"https://server1" : '*'
});
</script>
Step 3:
Now, you can make an AJAX call to the proxy.html as endpoint from server1. This is bypass the CORS request. The library internally uses iframe solution which works with Credentials and all possible methods: GET, POST etc.
Query ajax code:
$.ajax({
url: 'https://crossdomain_server/proxy.html',
type: "POST",
data: JSON.stringify(_data),
dataType: "json",
contentType: "application/json; charset=utf-8"
})
.done(_success)
.fail(_failed)

cross domain request data using pure javascript

I am trying to access an external url which returns json data and based on one of the value in that data I need to hide a table row. I have tried several options to do this with jsonp, jquery and ajax but nothing seem to work. YQL is working for me but I can't use outer Service as the code need to be independent. Please someone let me know how I can make this work with javascript
This is one approach I have tried
<script type='text/javascript'>
function checkBlueLight() {
$('#trBlueLight').hide();
$.getJSON('http://.../Lights/getBlueLight?callback=?', function (data) {
if (data.expDate != null) {
$('#trBlueLight').show();
} else {
$('#trBlueLight').hide();
}
});
}
</script>
This is another approach I have tried. same issue unauthorized - 401
$.ajax({
url: 'http://.../Lights/getBlueLight',
dataType: 'json',
success: function(data) {
if (data.expDate != null) {
$('#trBlueLight').show();
} else {
$('#trBlueLight').hide();
}
}
});
I have even tried to get data from url using jsp with and that also causing some permission issue
Do you control the external url? Because you can do:
On your local page:
function your_function(data) {
alert(data.message)
}
And then on http://www.include.me/remote.php (or whatever is returning JSON) you would have it return
your_function({message: "it works!"});
And then back on your local page:
var script = document.createElement("script");
script.setAttribute("type", "text/javascript");
script.setAttribute("src", "http://www.include.me/remote.php");
document.getElementsByTagName("head")[0].appendChild(script);
Which will then include the script, which simply tells it to run your already defined function with the data it provides.
If you can't control the external URL, and it doesn't support CORS nor JSONP, then you best option is to write a server side proxy method for the service. So on your server, you expose a new endpoint on your own host that on the server side access the real service on your clients behalf, and returns the result to your client.
For using jsonp, the server should bind the return type with a callback function. If it not, you cannot get the data from server.
If you are using cors, server should support that. Which means server should set,
"Access-Control-Allow-Origin" header to "*"
The issue with JS or jQuery is that crossdomain data may not be possible depending on the browser or server or a combination of both that prohibits the data exchange. This is security policy on many browsers and servers.
The best and safest choice is using a combination of JS or jQuery (Ajax call) with PHP cURL where the cURL will make the call requesting the data xml/json format and then sent back to the Ajax request.
Please take a look at the following example:
In the JS/JQuery AJax script:
$.ajax({
url: 'php_script_with_cURL.php',
dataType: 'json',
data:'THE_DATA_OR_REQUEST',
type:'post',
success: function(data) {
if (data.expDate != null) {
$('#trBlueLight').show();
} else {
$('#trBlueLight').hide();
}
}
});
and then in the php file (must be in the same server as your JS):
(you can use url string or post to request the data)
//USE POST IF YOU NEED TO SEND VARIOUS COMMANDS TO GET THE DATA BACK
$post = $_POST;
//INIT THE CURL CALL
$curl = curl_init();
curl_setopt_array($curl, array(
CURLOPT_RETURNTRANSFER => 1,
//this will tell the server how to return the data format
CURLOPT_HTTPHEADER => array('Content-type: application/json'),
//use the query string if require, if not just remove it
CURLOPT_URL => 'http://THE_URL_HERE.COM?request_value=some_value',
//use the post only if yo need to post values
CURLOPT_POST => 1,
CURLOPT_POSTFIELDS => array(
value1 => $post['value1'],
value2 => $post['value2']
)
//alternative you can also pass the whole POST array
//CURLOPT_POSTFIELDS => $post
));
$data = curl_exec($curl);
if(!$data){
die('Error: "' . curl_error($curl) . '" - Code: ' . curl_errno($curl));
}
curl_close($curl);
//echo the data that will be sent to the JS/JQuery Ajax call
echo $data;
//or if you need to do more processing with php
//$response = json_decode($data);
Hope this helps :)
Happy coding !

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